Biomedical subjects

O Castro-e-Silva Júnior

Publications and source records attributed to O Castro-e-Silva Júnior.

12 recordsLinked to original sources

PubMed1992

Hepatic morphology changes after hepatic artery ligation in extrahepatic cholestasis.

The present study was performed to correlate changes in hepatic morphology with hepatic artery ligation (HAL) in the presence of extrahepatic cholestasis (EHC). The study was conducted on 36 male Wistar rats weighing 350 to 400 g, divided at random into four groups of 9 animals each: group I, sham operation (control); group II, HAL; group III, bile duct ligation (BDL); group IV, HAL plus BDL. After seven days, liver fragments were obtained for morphological study. The relative volume of the bile ducts was I > II < III and III > IV (P < 0.05). These data indicate that arterial irrigation is important for the nutrition of the biliary tree. Seventy-six percent of the animals submitted to HAL plus BDL showed hepatic necrosis. In general, the liver probably becomes more dependent on HA flow in the presence of EHC.

Animals↗

PubMed1991

Integrity of liver inner mitochondrial membrane in rats with extrahepatic cholestasis.

To investigate the effect of extrahepatic cholestasis on integrity of the inner mitochondrial membrane, a study was conducted on two groups of rats: sham-operated control animals (N = 10) and rats subjected to extrahepatic cholestasis (EHC, N = 10) by double ligation of the hepatic duct. The animals were observed for 7 days and then sacrificed. The EHC group presented significantly higher serum levels of alanine aminotransferase, total bilirubins and alkaline phosphatase than the controls (P less than 0.01). Basal mitochondrial respiration (state IV), analyzed separately using either alpha-ketoglutarate or alpha-ketoglutarate + pyruvate as substrates, was similar in the two groups (P greater than 0.01). ADP-activated respiration, state III, diminished significantly in the EHC group. The results show that the decrease in mitochondrial function that has been reported by several investigators to occur in EHC is due to mitochondrial alterations not related to the ability of these organelles to maintain the proton gradient, since the inner mitochondrial membrane continued to be energized throughout the observation period.

Alanine Transaminase↗

PubMed1990

Serum gamma-glutamyl transpeptidase in chronic extrahepatic cholestasis.

Studies in the literature have shown the inhibitory action of bilirubin on serum gamma-glutamyl transpeptidase (GGT) activity. In spite of this, GGT is a sensitive diagnostic indicator, comparable to alkaline phosphatase for the diagnosis of chronic extrahepatic cholestasis (CEHC). To evaluate the relationship of bilirubin, alkaline phosphatase (AP) activity and GGT activity in CEHC we studied 30 patients with CEHC divided into two groups: A, 14 male and female subjects with serum bilirubin levels of 2 to 10 mg/dl, and B, 16 male and female subjects with serum bilirubin levels of 10.1 to 44 mg/dl. Serum GGT activity was measured by diluting serum samples 1:5 and 1:10. GGT values were equivalent in the two groups, there was no correlation between bilirubin and GGT (r = +0.179, P less than 0.01), and there was a significant correlation between GGT and AP (r = +0.627, P less than 0.01). The present results show that, if GGT inhibition by bilirubin did occur, this inhibition was not sufficient to prevent the increase in serum GGT levels and that the sensitivity of GGT as a marker for CEHC is similar to that of alkaline phosphatase.

Alkaline Phosphatase↗

PubMed1990

Inhibitory effect of different anticoagulants on gamma-glutamyl transpeptidase activity.

Increased gamma-glutamyl transpeptidase (GGT) levels have been observed in patients with several types of liver diseases. However, since GGT activity can be inhibited or increased by several substances, the interpretation of these increased levels should be made with caution. The present study was designed to determine plasma GGT activity in blood samples obtained from 24 adult volunteers (13 males and 11 females aged 20 to 40 years) with the use of three different anticoagulants, i.e., ethylenediaminetetraacetic acid (EDTA), calcium fluoride and calcium citrate, and to compare it with GGT activity in serum obtained from the same blood samples. Serum GGT activity was significantly higher than plasma GGT activity (P less than 0.001) and significantly higher in men than in women (P less than 0.05), though plasma GGT activity was similar for both sexes.

Adult↗

PubMed1990

Serum transaminase levels in the acute phase of chronic extrahepatic cholestasis.

Serum alanine aminotransferase (ALT) and serum aspartate aminotransferase (AST) levels are normal or discretely increased in rats with chronic extrahepatic cholestasis (CEHC). During the acute phase (first 72 h after biliary obstruction), however, serum transaminase values are quite elevated due to a mechanism not yet fully elucidated. Thus, this is a good experimental model, not involving hepatocellular necrosis, for the study of serum ALT and AST levels during the acute phase of CEHC. Male Wistar rats (250-350 g) were divided into two groups: group A (N = 60) was submitted to sham operation for bile duct ligation (BDL), and group B (N = 60) was submitted to BDL. Thirty and 120 min after BDL there was a 1.5-fold increase in both serum ALT and AST levels compared to sham-operated rats (P less than 0.05). Serum ALT levels were higher than AST levels as early as 30 min after BDL and the highest serum values for both transaminases were observed at 360 min which was also the last value measured. Serum AST levels increased 120 min after BDL, with no further significant increases thereafter.

Alanine Transaminase↗

PubMed1990

Effect of hepatic artery ligation in rats with chronic extrahepatic cholestasis.

Because of the liver's dependence on arterial blood to exert its metabolic functions in cirrhosis of the liver, with or without thrombosis of the portal vein, the interruption of hepatic arterial flow for the palliative treatment of malignant tumors of the liver is counterindicated. However, the effects of arterial devascularization on the cholestatic liver are not fully understood. The objective of the present study was to investigate hepatic alterations due to hepatic artery ligation in rats with chronic extrahepatic cholestasis. Serum alkaline phosphatase, bilirubin and alanine aminotransferase were measured in rats 3 h after sham operation (group A, N = 29) or ligation of the hepatic artery (group B, N = 29). Alanine aminotransferase activity was significantly higher (P less than 0.05) in group B, demonstrating acute hepatocellular damage in animals with chronic extrahepatic cholestasis.

Alanine Transaminase↗

PubMed1989

Heparin-induced increase in plasma and serum gamma-glutamyl transpeptidase activity.

gamma-Glutamyl transpeptidase (GGT) activity may be a sensitive index of hepatobiliary dysfunction. GGT activity, however, has been shown to be affected by several factors in different clinical situations. The present study was designed to determine the effect of heparin on serum and plasma GGT activity. Blood samples were collected from 15 normal male Wistar rats weighing 200-250 g for the determination of GGT activity in plasma prepared with heparin (group P(H), N = 10), in serum (group S, N = 15) and in serum with heparin added (group S + H, N = 10). GGT activity was 45.1 +/- 9.5 U/l (mean +/- SD) for serum compared with 161.2 +/- 46.1 U/l for serum plus heparin and 93.3 +/- 30.9 U/l for plasma prepared with heparin. The mean for each group was significantly different from the means for the other groups. These data demonstrate that GGT activity measurements should be made on serum in the absence of heparin, which produces elevated results.

Animals↗

PubMed1989

Effect of hepatic artery ligation on liver metabolism in rats.

The rat is an experimental model of orthotopic liver transplant that does not need arterial revascularization of the transplanted liver. The objective of the present study was to investigate the effect of hepatic artery ligation on hepatic metabolism in rats. After 2, 3 or 24 h of hepatic artery ligation, no significant differences in serum levels of alanine aminotransferase were observed. Bile flow decreased significantly 3 h after arterial ligation (P less than 0.05) and returned to normal after 24 h (P less than 0.05).

Alanine Transaminase↗

PubMed1989

Lack of correlation between the sulfobromophthalein test and fatty liver in diabetic dogs.

The present study was performed to evaluate the correlation between fatty liver and liver function in diabetic dogs. Experimental diabetes was induced in 14 dogs by total pancreatectomy or by alloxan administration, and partial (30%) hepatectomy was performed. Diabetic dogs were compared with control dogs (N = 7) subjected only to partial hepatectomy (30%). Control and diabetic dogs were submitted to the sulfobromophthalein (BSP) liver function test. Serum BSP retention was increased in diabetic dogs but there was no correlation with the extent of fatty infiltration of the liver.

Animals↗

PubMed1989

Effect of chlorpromazine and biliary drainage on portal blood flow and mitochondrial function during extrahepatic cholestasis.

The present study examines the effect of chlorpromazine and biliary drainage in cholestatic rats. The time course of portal blood flow was studied 24, 48, and 72 h and seven days after bile duct ligation. Portal blood flow decreased after 72 h. Chlorpromazine reduced biliary hydrostatic pressure in sham-operated control rats, but 24-h obstruction was sufficient to prevent this effect in cholestatic rats. The drug ameliorated the mitochondrial and cell membrane function of cholestatic rats before and after drainage. The data present further support for the role of ischemia in cholestasis.

Alanine Transaminase↗

PubMed1989

High chlorpromazine doses and liver function.

The aim of the present study was to evaluate the in vivo effect of high chlorpromazine (CPZ) doses on hepatocellular function. Thirty male Wistar rats weighing 200 to 250 g were divided into two groups: control (C, N = 17), injected ip with saline, and CPZ (N = 13), injected ip with high chlorpromazine doses (initial dose of 30 mg/kg body weight followed by daily doses of 10 mg/kg for 7 days). No significant differences in serum levels of alanine-aminotransferase, alkaline phosphatase and bilirubin or in mitochondrial function (activated and basal respiration and mitochondrial respiration control (activated/basal ratio) were detected between the two groups.

Alanine Transaminase↗

PubMed1988

Portal flow and mitochondrial function during extrahepatic cholestasis.

This study was designed to determine portal blood flow and mitochondrial and hepatic function during extrahepatic obstruction. Twenty-two male Wistar rats which had undergone bile duct ligation were compared 7 days later to 20 sham-operated controls. Portal flow and mitochondrial respiratory control ratio were reduced by 50% and 35%, respectively (P less than 0.01), and serum alanine-aminotransferase levels increased significantly (P less than 0.01) in the extrahepatic cholestatic group. These results suggest that cholestasis may cause an imbalance between the energy supply and the high demand of the liver leading to a state of partial ischemia.

Alanine Transaminase↗